Tap.



P. J. GREBEL.

TAP.

APPLICATION TILED AUG. 28. 1911.

1,059,453. Patented Apr. 22, 1913.

3 SHEETS-SHEET 1.

COLUMBIA PLANOGIAPH ICO.,\VASNINOTON, D.

P. J. GRBBEL.

TAP.

APPLICATION FILED AUG. 28, 1911.

059 453; Patented Apr. 22, 1913.

3 SHEETS-SHEET 2.

jzzfenzar P. J. GREBEL.

TAP.

APPLICATION FILED we. as, 1911.

Patented Apr. 22, 1913.

3 SHEETS-SHEET 3.

aity is v TED l STATES PATENT OFFICE l PAUL J. GREBELI OF CHICAGO,lILLINOIS.

TAP.

To all whom it may concern: a

, Be it known that LtPAULxJL GREBEL, a citizenof the United States,residing at Chicago county of coolnfitate of Illinois, have invented acertain :new and useful Improve mentinTaps, and declare it the followlngto lied to the particular number of parts in be a full, clear, and exactdescription of the same, such as will enable jot-hers skilled in the artto which it pertains to make \anduse i the same, reference being badItothe accompanying drawings, which a form at part of thisspecification: p

The primary object of myinvention is to produce a simple: and efficientcollapsible ta l l it further object of my invention is to produce a tapwhich may be nicely adjusted to takeup wear and whichjmay be sharpenedwithout changing its effective diameter.

A further object iOf myinvention is to produce a collapsible tapwhich,:in working, acts the same as a one-piece tap.

A further object 10f my invention :isto produce a collapsible tap devicein which the tap will be automatieally collapsed after the desirednumber of threads have been cut.

The various features of :novelty whereby my invention is characterizedwill hereinafter be pointed aout with particularity in the claims; but,for a full understanding of my inventiomand of its various objects,includingthose heretofore enumerated, among others, reference may be hadto the follow-i ing detailed description taken: in connection with theaccompanying drawings, wherein:

Figure 1 is a to plan view of adevice arranged in accorc ance withflapreferred form ofmy inventionyFig. 21 is a;central vertical sectiontaken :through the longitudinal axis of the device shown 1n;F1g. 1;

3 is a view looking toward the right 1T1 Figs. 1 and 2; Figs. 4, 5,6 and7 are respectively sections on lines l- 4:, 55, 66, and 77 ,0f Fig; 2;Fig. 8 is a View of the device partly in plan and partly in section;

Fig. ;9 is a plan view of one end of the de-;

viceywith a portion of ;the1casing1broken away; Fig. 10 is aviewsimdanto Fig. 3 showing a different position oflthe parts;

and Fighll is a detail showing the connection of one of the chasersortap members with the adj usting 1 member.

Specification of Letters Patent.

Applicationifiled August 28, 1911. Serial No. 646,391.

Patented Apr. 22, 1913.

Inthe drawings I have illustrated my invention 13S embodiedin a devicehaving three-part tap and, for the sake of brevlty,

I shall confine the a detailed description to thissingle embodiment; butitwill of course be understood that my invention is not lim:

the tap any more than it} is to certaln other structural details which11 have illustratedr upof a series of cylindrical bars lying side byside in engagement with, each other and having rolling contact on eachother. In this way ithe several bars mutually support each otherthroughoutthe length of: the tap and therefore givleto the tapsubstantially the stiffness and rigidity of a singlesolid member. a Apiece is cut away at one end of each of the bars so asto provide aniedgein whichithecutting teeth may be formed. It :is evident thatby rollingt-he bars :upon each other; each about its ow ntaxis, the radial.distance fromthe axis of thetap to the cutting edges is variedl I makeuse of this principleto secure accurate adjustment of the tap so as toobtain just the desired diameter :and also for the purpose of collapsingthe tap so as to permit it to be withdrawn from the tapped opening by adirect axial movement; it being seen that if lthe rotation of eachof thebars is great enough, thecutting teeth will be drawn so far toward thecenterof the tap that they will clear the threadswhich have been outthereby in the work.

by sidein engagementwith each other. Sections are cut away at the sidesof the bars atcorresponding ends as indicatediat:

2.1 This produces cuttinged es as indicated at 8, and in these cuttingec ges areformed a the teeth 4.- of the tap. The several bars are heldinproper relation to each other within a suitable casing 5 which haspreferably an elongated neck (S at one end thereof for :the purpose ofgivlng a bearing surface of considerable length. a The 1 bearing opening17 through the neclr preferably takesjust the shape of the crossSBCtlOIlzOf the assembled bars, thereby causingthe proper relation beqtween the bars to be maintained at all times.

Eachlof the barsis provided with a hook8 at the end opposite that havingthe teeth,

llO

. this arrangement necessitates the withdrawal.

the several hooks being adapted to engage with a head 9 on the end of anadjusting stem 10; the parts being so proportioned that when the threebars and the adjusting stemare assembled together with the several hookshooked over the head. of the adjusting stem, relative axial movementsbetween the severalparts is prevented but. each part is free to rotateabout its, own'axisb- The elements whichI have heretofore de-- scribedareso proportioned thatthe cutting ends of the several bars project outbeyond the neck of the casing when .thebars are assembled in the casing;with the adjusting memberiextending out through the back of the casing.The adjusting memberpreferably extends through an elongated neck 11which forms the shankby which the tool is held, the outer end of thestem being screw- .threaded as at-12 so as to permit it to be screwed inand out for thepurpose of varying the extent to whichthe tap projects heyondthe casing. After the desired longitudinal adj ustment has beenobtained the ad.

integral head provided with the neck 6, the

other end of the casing being open andbeing closed when the parts areassembled by means i of the shank 11 which is screwthreaded into theopen end of the casing as indicated at 14. As will hereafter appear,

of the members of the tap through the rear of the casing. If desired,however, the neck 6 may .be bushed, the bearing opening 7 being arrangedin the bushingand the diam:

A eter of the bushing being great enough to permit the withdrawal of thetap members with the bushing. Such a bushing will also have .t eadvantage of being a replaceable member for which;,a new one may besubstituted whenever the bearing becomes worn.

Surrounding the tap at a point within the casing is a heavy collar 15which is free to rotate through a limited angle about the axis of thetap and has also a limited movement in the longitudinal direction. Aswill" be seen most clearly from Figs. 2 and 7, the member 15 is providedwith a series of in ternal'longitudinal grooves or channels 16corresponding in number with the number of bars in the tap. Each of thebars. has a rounded lug 17 which extends into one of the grooves orchannels in the-surrounding collar; This arrangement permits the collarto :be moved in the longitudinal direction'withagain in its adjustedposition.

out disturbing thetap elements but if the collar is rotated each of thetap elements will be swung: about its own axis. It will thus be seenthat -by-turning the collarinone-direction or the other the cuttingteeth on the tap will be moved in or out depending upon the 1 directionin 'which the collar is turned; this manipulation of the collar servingto bring the .tapfromja working position toea collapsed positionand viceversa.

In the front face of thelcollar is a shallow segmental notch 18'largefenough to receive loosely a segmental block;19 rigidly securedwithin the casing directlyin front of thecola lar. It will'be seen thatwhenthe collari is turned so i as I to bring the notch opposite .the.block 'l8and is then pushed forward so that the blockisreceived in thenotch',tthe col lockedagainst rotarymovements, this being lar andconsequently the tap elements are 1 thecondltion 1n whlchthe parts areplaced during the cutting operation. After aholer has been tapped thecollar isslidback and tap and permit its withdrawal "from the tappedopening. It is not necessary that the i isthen free-to be turned so asto collapse the block fit snugly into the notch because the. v tap turnsonly in one direction during the cutting process andtherefore,,ifythere' is a slight lost motion between the block and thecollar, this will be taken up-at, the beginning of the cutting processand the'tap elements will thereafter be, rigidly held. I make use of theblock 19 to adjust the diameter of the i tap within limitsd'ependingupon the size;

of the tool. It willbe seen that byshifting the angular position ,of theblock in one direction, the collar will be brought to rest with thecutting teeth of the tap a little closer to thecenter ofthe-tap thanbefore the tap is reduced. By shift-ing theblock 1 angularly in theopposite direction the. turni ing of the collar and'of the taplelementsis r not arrested until the cutting edges have traveled outward awayfrom the center of the tap so that the effective diameter of the tap isgreater than it :was before." The ad-.

justment of the block 19 may conveniently be effected .by securing;theeblock in place by means of a stud 20 which passes through anelongated slot 21. in the casing. By loosening the stud,flor a nutthereointhe block may be shifted angularly within the limits of theslot, andmay then be locked In the arrangement shown the stud isprovided with a nut 22 on its outer end and a curved washer 23 is placedbetween-the casing and thenuu The washer may be provided with a suitableindex 24 which cooperates with a graduated scale 25 on the casing,;thereby enabling the workman to set the block rapidly and accurately.The collar maybe moved both angularly and longitudinally by means of a,

1 05 and consequently the effectlve diameter of suitable handle 26secured lthe'reto i and projectingupwardly outof the casing through anelongated slot 27 which{ is alsoowide enough to permit a limitedmovement of the handle longitudinally of 1 the casing. 1 By means of thehandle the tap elements maybe turned in either direction landmay belocked together in the, manner heretofore explained.

It is desirable that devicesof this kind shall be more or lessautomatic, thereby de-,

creasing the time required to tap an;opening and leaving the workman asfreeas possible to give his attention elsewhere. To this, end I havevprovided means whereby the, tap will beautomatically collapsed when-1ever, a predetermined; number of threads have been cut in a piece ofwork, the tap being againyplaced in its cutting; condition and lockedthere upon a simple manipula-i tion by the workman of the handle 26. In

1 the arrangement shown thereiis placed bee hind the collar 15 a coiledspring 28 one end of which bears against a stop 29 :fixed to the casingand the ,other end of which bears against a pm or stopz 30projectingean; wardly from, the: collar.: The spring ;is

made long enough so that when placed in position it isunder anfinitialtension and the stops are so located that the tension of; the spring1s1exerted in :thedirection to collapse the tap. A second springy31isplaced betweenthe collar and theirear :end

of the casing, this springbeing also under an initial tension andtending simply to push the collar forward, Slidablymounted on the neck 6of the casing is a follower 22 which has an inwardly extending flange 33extending into proximity to the tap. Normally the flange33 is at someZCllStELIlCG in front of the front endflof the=neck so that the followeras a whole may be moved :back a limited distance. Projecting back fromthe follower, preferably at diametrically cap-v posed points are pins 34lWhlOh extend through the front wall gQf the casing and engage with thefront face of the ring or collar 15. The movement of the follower issufficient to permit the pins, when the follower is pushedbaclgto forcethe collar away from the stop block, leaving the collar free to turn. Assoon asthe collar is free from the blockthespring28 expands and rotatesthe collar as.far:as it willi go, thus collapsing the tap. \Vhen thepressure upon the follower is removed the spring 31 moves the collarforward until its front-face strikes the block19. However, the: notch:in the collar no longer registers with the block and therefore thecollar and the block are not interlocked withieachother. To replace thetap in working, condition itis, only necessary for the workman to swingthe handle 26 from the position indicated in Fig. 10 toward or past thepositiongindicated in Fig; 3, this bringingmthe notch into registration:

forward.

with the block and the spring;311 thereupon forcing-the collar forwardfar enough to seat the block into the notch and thus lock thetelementsof the tap in their workingi position. It will, of coursebe understood 11 that the tap is adjusted by means of the ,ad-

justing stem so that it projects just far 1 enough beyond the flange ofthe follower to cause the follower to be engaged by the work and forcedback so as to collapse the tap just as the tappingof the ,holeain thework is completed. It i will thus be seen 1 that the tap automaticallydisengages itself i from the work atthe end of the tapping operation andis held in its collapsed condition 1 until the workman pulls upon thehandle 26., In this way thcre is no danger that the tap willbecomereengaged with the work after it has once been disengagedtherefrom and consequentlythe tap maybe drawn out of the work or thework drawn away from the tap without paying any further attention to thetap. Similarly afterthe workman pulls, the handlefor the purpose ofexpanding the tap again, he is not required to pay any 1 furtherattention to thetap because it is automatically locked and staysin thelocked conditionuntil it is released automatically through itheoperationof the follower or,

manually byla backward pull upon the a handle 26. a

It will thus beseen that I have provided a simple and eflicient,collapsibletap; which\ is almost wholly automatic in. its action;:;

which obviates the necessityof jnnscrewing 1 0 the work from the tap;{tIlClWlllCll permltsa the tap to be adjusted accuratelyto take upwear-.1, It will furthermore be seen that I have provided means wherebythe number a of; threads to be cut may be varied quickly 1 5 ingmovement of the cutting teeth as the 1 tap is collapsed and I have foundthat this, 1

effectually removes the dust- ,and keeps the tap clean; The cutting,edges on thetap elements or chasers may be made as long as is desiredsothat whenever it is necessary tosharpen the tap a little can be ground:olf the end thereof and the whole tap maytheni be pushed forward adistance equal to the depth of the portion ground ofl. Thus theeffective diameter of the tap is not decreased i but instead a sharpcuttingedge is formed a at the end of the tap and an entirely new tooth:or part of a tooth isbrought out into the cutting 120116 by bodilyshifting the tap for supporting said members in rolling contact witheach other, correspondingends of saidmembers projecting from said casingand having cutting edges thereon, means for locking said members agalnstrelative rotarymovements with the cutting edges inv cutting positions,and means for rolling said members on each other when in unlockedcondition so as to swing sa d cutting edges 'inwardlyutoward the axis ofthetap.

2. In a device of t-hecharacter described, a tap comprising a pluralityof cylindrical members, a casing having bearings therein for supportingsaid members in rolling contact with each other, corresponding ends ofsaid members projecting from said casing and having cutting edgesthereon, means for lockingsaid members against relative rotary movementswith the cutting edges in cutting positions, a work-engaged partcooperating with said means to unlock said members, and means forrolling said memhere on each other when in unlocked condition so as toswing said cutting edges inwardly toward the axis of the tap.

3. In a device of the character described, a casing, a tap dividedlongitudinally into a plurality of members each supported in said casingso as to be revoluble about an axisparallel with the axis of the tap andslidable longitudinally, one endof the tap projecting beyond the casingand having cut-ting edges thereon,.a member carried by the casing andadjustable in the direction of the axis of said tap, a connectionbetween the latter member and the members of the tap holding themagainst relative long tudinal movement and permitting relativeturning.movements,

and means. for turning the members of the tap relative to each other soas to bring the cutting edges into working. positions or carry theminwardly toward the axis of the tap into inoperative positions.

4.- In a device of the character described,

a casing, a tap mounted in the casing and projecting therefrom at oneend, said tap.

comprising a plurality of cylindrical memberslying side by side inengagement with.

each other, means for holding the members of vthe tap againstlongitudinal movement, a collar surrounding said tap at a point withinthe casing, said collar having aflimited turning movement about the axisof the tap and a limited movementlongitudinally of the tap, cooperatingshoulders on the collar and on the casing arranged to be interlocked Lwith each other upon alongitudinal mov'e' ment of the collar, aspringfltending normally to hold the collar in the position in whichsaid shoulders are interlocked, a

spring tending normally torotate said @01- lar, said collar beingprovided with a pluralityof internal longitudinal grooves orl recesses,lugs on the members'of the'tap projecting into and having a sliding fitin said grooves or recesses, and awork-engaged part" cooperating withsaid collar to move it lon-. I

gitudinally far enoughto bring said shoulders out of engagementwith eachother,

5.'-In a device of the character described, a casing, a tap comprising aseries of Cylll'l;

drical members lying side'by side in'engager ment with each other andreach revolubly supported in said casing, one endof each of said membersprojectingbeyond the casing and having; cutting edges thereon, a

member carried'by the casing and adjustable in the direction of the axisof said tap, a

connection between the lattermember and, the members of the tapholdingthem against relative longitudinal movement andpermittingrelative turning movements, and means for rolling the membersof the tap upon each other so as to bring the cutting edges into"working positions or carry them inwardly" into inoperative positions. I

6. In a device of the character described, a casing, 'a tap mounted inthe casing, and

projecting therefrom at, one end,said tap comprising a plurality ofcylindrical members lyingside by side inengagement with each other,means for holding the members 3 of the tap against longitudinalmovement, a collar surrounding said tap at a point within the casing,said collar having a limited movement longitudinally of the tap, cooperating shoulders onthe' collar and onthe J casing arranged to beinterlocked witheach other upon a longitudinal movement ofthe collar,said collar being provided with a plurality vof longitudinal grooves orrecesses, lugs on the members of the tapprojecting into and having asliding fit in said grooves or recesses, and means for actuating said 1collar. I I

7. In a device of the character described,

a tap comprising a plurality of cylindrical members lying side by sidein engagement with each other, a casing'surroundingfone end of saidmembers and havmgbearings olubly incontact with each other, the otherend of said members having cutting edges. v

8. A tap comprising a series of cylindrical members lying side by sidein engagement with each other and'having cutting edges therein formaintaining said members revon correspcndin gends, :and means for hold?responding ends of said cylindrical members 1 ing said members inrevoluble engagement being provided with cutting edges. 10 with eachother. i In testimony whereof, I sign this speci- 9. A tap comprising: amember having a ficaticnd in the presence of two Witnesses. 5cylindrical bore therethrough andia plurality PAUL J. GREBEL.

of cylindrical: members lying Within said Witnesses: bore and eachmaking; contact with ;the W'ih F. FREUDENREICH, others and WithZthe Wall101: the bore,z cor- RUBY 1V. BRYDGES.

Copies of this patentmay be: obtained for :flvecentseach, by addressingthe: "Commissioner of Patents,

Washington, D. O. i

